Yes, that script Neirao suggested is good for poly reduction... The problem is that it's not able to simplify an arbitrary mesh, it can only work with a mesh created by subdivision algorithm.

I've been working on a general poly reducer for a while and it's already finished, but the script execution takes several hours if the mesh has more than 2000 polys... I guess the algorithm needs some kind of optimalization I hope to post it soon, stay tuned...